Sheet feeding mechanism



J. w. MILLER SHEET FEEDING MECHANISM Filed Aug. 12, 1955 April 1, 1958INVENT0R.. JOHN W MILLEQ United States Patent,

SHEET FEEDING MECHANISM John W. Miller, Benton Harbor, Mich., assignorto F. P.

Roshack Company, Benton Harbor, Mich., a corporation of MichiganApplication August 12, 1955, Serial No. 528,083 11' Claims. (Cl. 271-62)This application is a continuation-in-part of my copending. applicationSerial No. 482,493, filed January 18, 1955, now Patent No. 2,739,810,dated March 27, 1956.

'In such prior application, I have disclosed apparatus intendedprincipally for use in the automatic feeding of paper sheets to awork-performing device, such as a perforator. The feed mechanismincludes an elevator for supporting and raising a stack of the sheets, atransfer device at a predetermined elevation above the elevator andoperative to remove the sheets successively from the top of the stack,and feeler mechanism for controlling the.

rise of the elevator in response to the top level of the stack. Theelevator drive is taken from the drive of the perforator, so as to be insynchronized relation therewith, and the connection includes a couplingwhich is under control of the feeler mechanism.

. The present invention is concerned with improvements in such feedmechanism which afford more flexible operation and enhance control ofthe same.

It is a primary object of the invention to provide a modified driveconnection for the elevator which will permit the same to be operated atvarying rates, thereby enabling the apparatus to handle sheets ofvarying thicknesses, for example, thin paper sheets as well as sheets ofcardboard, at optimum rates of feed.

Another object is to incorporate a safety feature which will protect thestructure in the event of improper operation or failure of the feelermechanism, whether this is due to a mechanical failure or to negligenceon the part of the operator.

The transfer operation, or the removal of thejsheets from the elevator,requires the suction or other unit employed for the purpose to belocated above the elevator, and the feeler mechanism should function tobring the sheets successively into such proximity that they maybestrippedfrom the top of the stack. Since the drive must besynchronized with the work-performing device, there is a driveconnection between the latter and the elevator, as indicated above.Accordingly, if the feeler is ineffective for any reason, the elevatorwould be continuously raised and either the stack or the platform itselfforced against the transfer device with damage to the structure.

In accordance with the present disclosure, an additional safety controlis provided and thetransfer device so modified that the presence of suchimproper force is im. mediately detected and applied to shut off theentire apparatus.

Other objects and advantages will become apparent .as the followingdescription proceeds.

To the accomplishment-of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described andparticularly pointed out in the claims, thefollowing description and theannexed "draw:

ingssettingforth in detail certain illustrative embodiments of theinvention, these being indicative, howevexy of but;

a few of the various ways in which theprinciple of the I invention maybe employed.

In said annexed drawings:

Fig. l is a side elevational view of sheet feeding mecha-' to whichreference may be had for the structure not included herein and notessential to a full and complete understanding of the presentimprovements. Such mechanism comprises a frame 1 Within which ahorizontal platform or elevator 2 is arranged for supporting a stack ofthe sheets indicated at 3. At each side, the platform is supported by abracket 4 attached to a section of chain 5, the brackets being guided byrollers 6 in engagement with the vertical frame posts 7.

The device for removing the sheets from the top of the stack supportedon the platform is in the form of a suction wheel or drum 8 securedcentrally to a shaft 9, for

rotation. The shaft is mounted in posts 10 located at the respectivesides of the frame and having vertical slots 11 within which the shaftis received and, accordingly, vertically movable.

Shaft 9 is adapted to be driven so as to rotate the suction drum in aclockwise direction as viewed in Fig. 1.

This drive comprises a split-cone variable-speed pulley 12, ofcommercially available type on a shaft 13, a fiat face pulley 14 on theshaft 9, an idler pulley 15, and a V- belt 16 arranged about thevariable speed and' idler pulleys.

thereby reversely to drive the shaft 9, and by mounting the idler pulley15 on a support 17 pivotally secured to the frame, the latter may beshifted to vary the belt ten sion with a resultant change in speed dueto radial move ment of the belt on the split-cone pulley 12 in wellknown manner.

Shaft 13 extends parallel to the suction'drum shaft 9" at the inner sideof the feed mechanism and has arranged thereabout in longitudinallyspaced relation a number of tapes '18 which deliver the sheets tothe'perfor ator unit, not shown. At its other end, the shaft 13 isdriven by such device by means of a pulley 19 and a belt 20, as fullydiscussed in my earlier application, and in such;

manner both the delivery tapes and the suction drum are driven inresponse to operation of the perforator.

The shiftable support of idler pulley 15 provides regulation of thesuction drum speed of rotation relative to Y the speed at which theconveyor tapes move, and this affords variable overlap of the sheets instream feeding.

Such adjustment is facilitated by an operating rod/21 7 secured to oneend of the idler supportandhaving its: ,other end threaded and passedthrough a bracket 22 on the frame. A thumb nut 23 is threaded on theouter end of "the rod for convenient manual positioning of the supportabout'its pivotal connection.

Small substantially horizontal guides 24 are positioned just beneath thesuction drum to provide for sliding move- I ment of the paper sheetstoward the conveyor tapes as a result of the lifting and carrying actionof the drum. A friction roll 25 is'provided to grip the leading'edge of?each sheet as thus transferred cooperably with one of the tapes toensure that the transfer is accomplished without slippage. i V 1 Suctionis applied to the. drum 8 by means of a shoe 26 overlying and heldstationaryat one end of the drum.

As customary, the adjacent end face of the drum is pro- Patented Apr. 1,1958 The belt is arranged so that its flat surface en-: gages the pulley14'at the lower portion of the latter,

vid'ed with a series of circumferentially spaced apertures 27, and afurther communicating series of spaced apertures. 28 is-provided in thecylindrical wall thereof. The shoe applies suction at the lowerperipheral portion of the rotating drum effective to pick up and carrya'sheet from the top of the stack a-predetermined distance snlficient totransfer the same to the conveyor. A hose 29, which has been shownpartially broken for convenience of illustration, extends from the lowerregion of the shoe 26 to a valve assembly 30 having a hose connection 31leading to asuitable source of suction, for example, a motordrivenblower, not shown. This valve assembly is of a known type adapted toprovide for either strike or stream feeding of the sheets by operationof a handle 32 controlling a barrel valve in the .main suction line.

Itwill be clear that the-top of the stack of sheets has a proper.operating level relative to the suction drum for the desired transferaction of the latter, and that, as sheets are successively removed, thestack should be elevated to maintain the top at such level. I provide,for this purpose, an automatically controlled drive and lift meansoperating on the platform support chains 5. The chains are engagedrespectively about drive sprockets 33 afiixed to shafts 34, the shaftsbeing supported for rotation in bearing assemblies 35. At the inner endof each shaft. 34 is a worm gear 36 and a transverse shaft37 is providedwith worms 38 at the sides of the mechanism respectively in drivingengagement with the worm gears. The gearing is such that rotation of theshaft in one direc tion, counter-clockwise in the illustrated structure,causes both chains to be actuated in a direction lifting the platform 2.

A latch bar 39 secured at one end of the suction shoe 26 has its otherend slotted and engaged about shaft 37, thereby to hold the shoestationary as the suction drum shaft 9 passing therethrough rotates. Atone side of the frame of the feeding mechanism, shaft 37 projectsoutwardly, has a ratchet wheel 40 secured thereon, and terminates in acrank handle 41. A pawl 42 is pivotally mounted on a pin held by spacedsupport blades 43 which are, in turn, rotatably mounted on shaft 37, thepawl being disposed for engagement with the ratchet wheel. Pawl 42 has alever 44 extending to the rear or oppositely from the ratchet-engagingend for rocking of the pawl about its pivotal connection with thesupport blades or cars 43.

Outwardly of such pivotal connection of the pawl, the upper end of acylinder 45 is attached between the ears 43 and reciprocably received inthe upper end portion of this cylinder is a first plunger 46. The upperend of this plunger is positioned beneath and in engagement with thelever 44" of the pawl, so that reciprocation of the plunger causes thepawl to oscillate between. positions engaged with and. disengaged fromthe ratchet wheel. In the normal depressed condition of plunger 46, thepawl is disengaged. A second plunger 47 is mounted likewise forreciprocation in the lower end portion of the cylinder 45 and isprovided with an adjustable collar 48 limiting upward movement of thesame or penetration of this plunger into the cylinder.

There is accordingly, defined within the cylinder and between theopposed ends of the two plungers a chamber 49 adapted to contain air anddimensioned so that air sealed therewithin is effective to transmit themotion of one plunger to the other. Accordingly, when the chamber isexhausted of air, therewill be no effective coupling between theplungers, butwhen filled and sealediwith air, I

the same forms a fluid connection therebetween.

The lifting thus imparted to the upper plunger, or theabsence of thesame, is utilized tocontrol engagement of the pawl with the ratchetwheel in the manner of a triggering action to complete or leave disabledthe driving connection of the shaft 37, as the case may be. Assumingchamber'49 to be sealed, initial'upward movement of plunger 47 causesplunger 46 to raise, thereby to rock pawl 42 from its normal disengagedcondition into engagement with the teeth of the ratchet wheel. Thislocks together the ears 43 and the ratchet wheel with respect tomovement in the direction of desired rotation of shaft 37. As plunger 47continues its upward travel, collar 48 thereon engages the lower end ofcylinder 45, and with further elevation raises the cylinder and hencethe outer ends of cars 43. The latter swing upwardly about the axis ofshaft 37, and since the ears are locked by the pawl relative to theratchet wheel, the shaft is rotatively advanced.

However, should air be permitted to escape from chamber 49, initialraising of the lower plunger will not result in rocking of the pawl fromits normal condition disengaged from the ratchet wheel, so thatsubsequent raising of the cylinder and swinging of the cars 43 will notturn the shaft. In such case, the ears are free to rotate relative tothe drum and shaft 37. Thus, the lower plunger 47 of the assembly may becontinuously reciprocated with transmission of the drive force to shaft37 under control of conditions in the cylinder air chamber. It is tobe'noted that a direct mechanical connection of structural elementsresults in the drive condition of the assembly, thereby making itpossible to lift heavy loads on the platform.

The protruding lower end of plunger 47 is pivotally attached to one arm50 of a crank member 51. Such arm has two possible points of connectionof the plunger indicated respectively at 52 and 53, these being in theform of openings through which a pin is passed to secure the plunger tothe arm.

The crank is pivotally connected to a support projection 54 of thehousing of the suction valve assembly 30 with the other arm 55 of thecrank extending upwardly. Arm 55 has-a connection by means of a yoke andpivot pin fitting 56 to one end of a rod 57 which is connected at itsother end eccentrically to an element 58 also driven by the electricmotor 59 of the perforator. Accordingly, operation of the perforatorcauses the rod to reciprocate substantially horizontally and this motionis transmitted through the crank to reciprocate the plunger vertically.Rod 57 also actuates the valve assembly 30 to apply suction to the drum8 likewise in synchronism with the perforator operation in a manner setforth specifically in my prior application.

A vertical support post 60 projects above the frame 1 at the corner ofthe same adjacent the pawl and ratchet drive assembly, and a rod 61 isattached thereto by a fittingGZfor swinging movement in a plane parallelto that of the elevator. Asensing assembly indicated at 63 isslidablymounted onthe arm and supports a depending valve and feeler unit 64. Asmall flexible conduit 65 leads-from the valve of such unit to thecylinder 45 at the central chamber 49 of the same, while the feeler arm66 extends downwardly into engagement with the top of the' 'sta'ck' onthe elevator.

The feeler-arm is adapted to be rocked upon raising and lowering of thetop of the stack relative thereto and, by'virtue of such action, tocontrol the opening and closing of the associated valve. When the top ofthe stack is at a predetermined level, the valve is operative to ventthe cylinder chamber 49 to the atmosphere, whereby the cylinder andplunger drive is ineffective to rotate shaft 37 and raise the elevator.However, when the stack top is below such level, the feeler swingsdownwardly and closes the valve which thereby seals air in the cylinderand results in the drive force being transmitted to'the elevator liftingmechanism. The detailed construction and a moreelaborate description ofthe operation of this feeler mechanism will be found in my application,Serial No. 482,493, now Patent No. 2,739,810, and further discussion isbelieved unnecessary-*here.

As stated in the foregoing, the shaft 9 and hence the suction drum 8 maybe lifted from the normal sup- N feeler is accidentally moved away fromthe stack and platform by an operator, so that it would remain in itsdownwardly extending. position inv which it closes the valve, the riseof'the elevator would not be interrupted.

To protect against damage resultingv from improper force against thesuction drum, I provide a safety feature which will immediately andautomatically shut ofi the entire apparatus upon the occurrence of suchforce. This safety comprises a limit switch 67 mounted by the post 60above the projecting end of shaft 9 at such side and having a plunger 68which extends downwardly into contact with the shaft. Accordingly,should the shaft be lifted, for any reason, the limit switch isactuated.

As shown in Fig.3, switch 67 is connected and normally closed in theenergization circuit of the perforator drum motor 59. Shifting of theshaft and suction drum upwardly from the full to the dashed lineconditions thereof illustrated opens the switch, whereupon the motorisde-energized and the drive of the elevator, and of the entireapparatus, is stopped.

It is further to be noted that the variable attachment of the cylindercoupling assembly to the crank 51 in the drive connection between theperforator and the elevator affords different rates of feed or rise ofthe elevator. That is, the two points of attachment 52 and 53 on thecrank arm 50 are unequally spaced from the axis of oscillation of thecrank and thereby afford different moment arms. Thus, when the lowerplunger 47 is attached to the point 52, as illustrated in Fig. 1, theshaft 37 is rotated in increments smaller than those resulting when theattachment is at the point 53 as indicated in Fig. 3. The firstarrangement thus corresponds to a slow feed position and the second to afast feed position, the operator being able to select between the twodepending upon the material being handled.

It will accordingly be seen that the feeding operation of the priormechanism has been made more flexible by the present improvements and,moreover, better protected against the possibility of serious andexpensive damage due to malfunctioning of the feeler device and itscontrol. It is now possible to handle elficiently in the same apparatusrelatively thick cardboard sheets as well as thin paper sheets, thedrive being set in the fast feed condi tion for the former in the slowfeed condition for the latter. While I have shown onlytwo such feedconditions, an even greater number of ditferent rates may readily be hadby providing added points of possible attachment for thecylinder-plunger unit on the drive crank, each affording a differentstroke of the unit. Within limits, a maximum degree of adjustment couldbe realized by the use of a slot in the particular crank arm along whichtheattachment could be made as desired.

Other modes of applying the principle of the invention may be employed,changes being made as regards the details described, provided thefeatures stated in any of the following claims, or the equivalent ofsuch, be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In apparatus for the feeding of sheet material to a work-performingdevice having an electric drive motor, an elevator for supporting andraising a stack of the sheets to be fed, a drive connection between suchmotor and the elevator including a pneumatically controlled coupling andan oscillatable member to which the coupling is adjustably attached,adjustment of such attachment afiording different rates of feed of theelevator, a

transfer device for removing the sheets from the top of the stack on theelevator, said transfer device comprising a suction drum and a shaft onwhich the drum is mounted for rotation, supports holding such shaft withmally closed limit switch mounted adjacent the drum shaft for actuationthereby upon lifting of the shaft, said switch being connected in theenergization, circuit of the electric drive motor, whereby suchactuation of the same de-energizes the motor to stop operation of theworkperforming device and of the elevator. l

2. In apparatus for the feeding of sheet material to a work-preformingdevice having an electric drive motor, an elevator for supporting andraising a stack of the sheets to be fed, an adjustable drive connectionbetween such motor and the elevator capable of adjustment to vary therate of feed of the latter, a transfer device for removing the sheetsfrom the top of the stack on the elevator, said transfer devicecomprising a suction drum and a shaft on which the drum is mounted forro tation, supports holding such shaft with the drum positioned abovethe elevator, the shaft and hence the drum eration of thework-performing device and of the elevator.

3. In apparatus for the feeding of sheet material to a work-performingdevice having an electric drive motor, an elevator for supporting andraising a stack of the sheets to be fed, a drive connection between suchmotor and the elevator including a pneumatically controlled coupling andan oscillatable member to which the coupling is adjustably attached,adjustment of such attachment.

affording different rates of feed of the elevator, a transfer device forremoving the sheets from the top of the stack on the elevator, saidtransfer device being supported above the elevator and capable of beinglifted from its normal operative position, feeler mechanism forconditioning such drive coupling of the elevator in accordance with thelevel of the stack top in relation to the transfer device, and anormally closed switch located to be actuated by the transfer deviceupon lifting thereof from its normal position, said switch beingconnectedin the energization circuit of the electric drive motor, whereby such actuation of the same deenergizes the motorto stop operation ofthe work-performing device and of the elevator.

4. In apparatus for the feeding of sheet material to a work-performingdevice having an electric drive motor, an elevator for supporting andraising a stack of the sheets to be fed, an adjustable drive connectionbetween such motor and the elevator capable of adjustment to vary therate of feed of the latter, a transfer device for removing the sheetsfrom the top of the stack on the elevator, said transfer device beingsupported above the elevator and capable of being lifted from its normaloperative position, feeler mechanism for controlling the drive of theelevator at its adjusted rate of feed in accordance with the level ofthe stack top, and a normally closed switch located to be actuated bythe transfer device upon lifting thereof from its normal position, saidswitch being connected in the energization circuit of the electric drivemotor, whereby such actuation of the same deenergizes the motor to stopoperation of the work-performing device and of the elevator.

5. In apparatus for the feeding ofsheet'material to a work performingdevicehaving an electric drive motor, an elevator for supporting andraising a stack of the sheets to be fed,.a drive connection between suchmotor and the elevator including a pneumatically controlled coupling, atransfer device for removing the sheets from the top of the stuck on theelevator, said transfer device comprising a suction drum and a shafton'whichthe drum is mounted for rotation, supports hOlding.suCh shaftwith the drum positioned above 'the elevator, the shaft and hence 'thedrum being movable upwardly relative to such supports, feeler mechanismfor conditioning such drive coupling of the elevator in accordance withthe level of 'the stack top in relation to the suction drum, and anormally closed limit switch mounted adjacent the drum shaft foractuation thereby uponlifting'of the shaft, said switch beingconnectedintheenergization circuit of the electric drivemotor,wherebysuch'actuation of the same tie-energizes the motor to stopoperation of the workperforming device and of theelevator.

"6. In apparatus for the feedingof sheet material to a work-performingdevice having an electric drive motor, an elevator for supporting andraising a stack of the sheets to be fed, a drive connection'between suchmotor and theelevator, a transfer device for removing the sheets fromthe top of the stack on the elevator, said transfer device comprising asuction drum and a shaft on which the drum is mounted for rotation,supportsholding such shaft with the drum positioned above the elevator,the

shaft and hence the drum being movable upwardly relative to suchsupports, feeler mechanism for controlling the drive of the elevator inaccordance with the level of the stack top, and a normally closed limitswitchmountcd adjacent the drum shaft for actuation thereby upon liftingof the shaft, said switch being connected in the energization circuit ofthe electric drive motor, whereby such actuation of the samede-energizes the motor to stop operation of the work-perfonningdeviceand of'the elevator.

7. In apparatus for the feeding of sheet material to awork-performingdevice having anelectric drive motor, an elevator forsupporting and raising a stack of the sheets to be fed, a driveconnection between such motor and the the elevator, a transfer devicefor removing the sheets from the top of the stack on the elevator, saidtransfer device being supported abovethe elevator and capable of'beinglifted from its normal operative posi tion, feeler mechanismforcontrolling the drive of the elevator in accordance with the level ofthe stack top, and a normally closed switch located to be actuated bythe transfer device upon lifting thereof from its normal position, saidswitch being connected in the energization circuit of the electric-drivemotor, whereby such actuation of the same dc-energizes the motor to stopoperation of the work-performing device and of the elevator.

8; Sheet feeding mechanism comprising a stack platform, drive meansincluding an electric motor and transmission means connecting said motorto said platform for raising the latter, a sheet removing devicepositioned normally .above the platform and mounted for verticalmovement, control means for regulating operation of said drive mcansinresponse to the elevation of the platform, and a control circuitfor saiddrive motor including a switchnactuated inresponse to lifting of thesheet removing devicento de-energize'the motor.

9. Sheet feeding mechanism comprising a stack platform, .drive meanshaving a connection with said platform for raising the same, sheetremoval and transfer means positioned normally abovethe platform andcapable of being moved upwardly from its.normal position, control meansfor regulating said drive means in accordance with the elevation of theplatform, and further control means operative to disable said drivemeans in response to lifting of the sheet removal and transfer meansfrom its normal'operative position.

10. Sheet feeding mechanism comprising a stack platform, drive meansfor'raising the same including an electric motorand ;transmission meansconnecting the same to "the platform, a sheet removing device mounted onashaft above the platform, hanger supports for said shaft permitting thesame and hence the sheet removing device to be moved upwardly, controlmeans for regulating operation of said drivemeans in response to theelevation of a stack of sheets on the platform, a normally closed limitswitch located above said shaft for actuation by the same when lifted;and a control circuit for said motor including such switch, suchactuation of the switch being effective toustop the -motor drive of theplatform.

11. In sheet feeding mechanism, an elevator for supporting and raising a.stackof the sheets to be fed, drive means for the elevator comprising ashaft, a cylinder,

latch means for interconnecting one end of the cylinder and the shaft, afirst plunger in the cylinder operative to actuate the latch means, asecond plunger opposed to the first and having a lost-motion connectionwith the cylinder, valve means for selectively venting and sealing thecylinder regionbetween the two plungers, control means forconditioningthe valve means in accordance with the elevation of a stackof sheets on the platform, the cylinder being sealed when .the stack isbelow a predetermined level whereby initial movement of the secondplunger causes the first tolatch the cylinder to the shaft, acontinuously driven i crank, and an adjustable connection between thesecond plunger and the crank, the lower plunger being driven by thecrankto drive the cylinder, adjustment of such plunger attachmentvarying the resultantstroke of the cylinder and hence the rate of feedof the elevator.

References Citedin the file of this patent UNITED STATES PATENTS1,521,094 Harford Dec. 30, 1924 1,939,589 Broadmeyer Dec. 12, 19331,956,475 Robinson Apr. 24, 1934 2,182,595 Novick Dec. 5, 1939 ,L2,739,810 Miller Mar. 27, 1956

